Review: Tube Audio Design TAD-1000 Tube amp


Category: Amplifiers

I bought a pair of Paul Grzybek's TAD-1000 Monoblocks about five months ago. Since then I've had a few queries on how I liked them so I thought I would post my own notes on setting them up along with a brief review. Hopefully, my system and experiences are enough different from others that this is worthwhile.

Setup

Follow Paul's directions. You definitely want to take your time in setting the bias and feedback and selecting your 'normal' listening mode - Triode (3) or Pentode (4). You have to do the bias first, of course (350-370 on all four on each amp after a 10-minute minumum idle warm-up). After that I would recommend that you set the feedback to mid-range of the knob travel. Pick your normal mode (Triode or Pentode) by switching the mode while you are listening to some well-known music. Then set the feedback on both monoblocks while listening to some familiar music.

I find I like the detail and clarity of the Triode wiring but others prefer the punch and boost of the Pentode mode. There are certain recordings that sound better with Pentode - some of the older Beatles stuff comes to mind. But, I usually leave the monoblocks set to Triode and just turn them up a bit, even when listening to something like Led Zepplin, instead of switching to Pentode - but you definitely get more power in Pentode. The feedback setting makes a LOT of difference in how the harmonics affect the sound reproduction. It's a trade-off. Adjust them until things sound true-to-life to your ear. You will want to do this with different types of music and music passages. It is probably best to use vocal, piano, and other mid-range passages to fine-tune the feedback settings. You will likely find that the perfect setting for one passage is not the same as the perfect setting for another recording or passage. It will also probably depend on the source. What's nice about the 1000's is that Paul gives you control of this trade-off instead of using a built-in setting.

For the gain controls on the back of the monoblocks, I would set them to just a bit off of full open - crank them all the way up and then back off about an 1/8th of a turn. I make this recommendation not out any specific technical basis, but just on my own belief that it is not a good idea to have any control set all the way to the stops as a permanent state of affairs. I use the gain controls in my own set up as a method of balancing the sound stage in my particular listening area.

Results

Once you've set up, you can start listening with a fair degree of musical pleasure. Break-in was noticeable but fairly short-lived. I would say not more than a few hours. During that time I did notice a few overly bright spots and some passages that sounded a bit 'jangly,' if that makes any sense to you. But nothing was persistently noticeable. After that short period, things have been very, very good in the listening department.

Bass is immediate and full. I have a home theater system with a subwoofer and a solid-state AV amp (Harmon-Kardon AVR520, Polk Audio RM-7 5.1 speaker system). I output from the Denon source to both the home theater system via a fibre-optic digital audio cable and to the stereo system via right-left RCA cables. For those of you not familiar with the Soliloquy 5.3 speakers, see specs below - they are not big thumpers. The bass through these speakers with the stereo setup rivals the bass of the home theater system - even at the vibrate-the-walls, impact-tremor level that is more felt than heard. This was so surprising to me that I toyed with the idea of getting rid of the home theater system and just using the stereo system for all sound reproduction. But, the home theater does offer the center speaker that makes dialog come through with such clarity - that and the surrond-sound effects make it worth keeping.

For the mid-range, vocals and piano, etc., the sound is right there. You can listen to Norah Jones, for example, close your eyes and imagine that you are sitting at a table right in front of the stage. Highs come through pure and bright and clear, without being obnoxious. The sound stage is broad and pervasive. I can sit at my desk across the room and to the side of the system's normal listening area and still enjoy music with very little reduction in the presence of the sound stage.

After having these TAD-1000's for a few months now, I can say I am more than happy with them. There are always improvements that can be made, but the addition of these monoblocks has given me my holy grail of sound. Well, at least for the time being. ;-)

Associated gear
Tube-Audio Design TAD-150 tube preamp with signature mods by Paul Grzybek

Soliloquy 5.3 Speakers - Each speaker has two 5 1/4" drivers and one 1 1/8" tweeter and is floor-standing with spikes.

Analog Source - Music Hall MMF-9

Digital Source - Denon 3910 with mods by Mike Powell (HRAM)

Similar products
Acoustic Sound Labs AQ-1006 845 monoblocks
bamabubba
A quick update.

I can't help myself! I keep searching for the next upgrade, change or tweak that will create a live performance in my home. My friend Harvey R., a fan of the older classic horn speakers, tells me it can't happen. Undoubtedly he is correct. Nevertheless, the pursuit continues.

Since my last remarks here, I have been through much tube rolling. I have used the JJ KT77s (a significant upgrade from the stock Svet EL34s - beware of getting the ones with the small diameter pins), some older Phillips 6550s (nice, round, warm comfortable sound, but not live sounding, some EH EL34s (leaner than the JJs; try if your bottom-end is a little heavy), Mullard EL34s (very good); Tungsol KT88s (very good, perhaps my second choice, although I would want to listen again to the:), Svetlana Winged Cs, also very good.

Before I tell you what I am using now, I would recommend that owners of the TAD-1000 listen to Paul G. regarding his recommendations for interconnect cables. I have some expensive high-end cables that were obliterated by the cables that Paul recommends. And that was before.

Before what? Well.... I have been seeing more and more tube vendors tout the benefits of cryogenic treatment. How could I not try it?

After doing lots of research and finding out which companies had been doing cryo processing on tubes (who wants to take a chance on shattering tubes), I sent my power conditioner, my power cords, my interconnects (I had bought an identical spare pair to use while I waited and for later comparison with the treated pair), and my precious vacuum tubes.

Remembering my experiences years ago with them in a different amp, I tried some EI KT90s in the TAD-1000. I have a friend who had 8, allowing me to try them. I quickly heard enough to know they were different than anything else to which I had listened in the 1000.

The EI KT90 tubes are not known for their reliability, and getting enough of them was a problem. Because of their scarcity, nn my search for them, I was unlucky to deal with one somewhat pompous California vendor, who shall remain nameless. This vendor advertises "triple platinum matching" and burn-in, but refuses to stand behind the sale of these tubes (in fairness, the guy made it clear in advance and did eventually offer to refund my money when it was clear that the triple platinum matched tubes he sent me weren't matched - that is, the measurements the vendor put on the side of the boxes were different, and the tubes measured that way in three of our own tube testers). I found the balance of my required tubes from an audiophile in Canada. What a contrast the buying experience was.

One other piece of the story is the front end tube. In my last epistle, I waxed eloquent over the performance of the EI Gold Pin 12AX7. It was (and still is) excellent, and depending on your system, it may still be the one to have. Nevertheless, my main tube guy, Sandy@levytubes.com), the best guy you'll ever buy anything from, had obtained a special run of some Sovtek (yeah, Sovtek!) 12AX7s. In a shootout with a bunch of vintage NOS 12AX7, 5751 and 12AU7 classics, as well as some of the newer offerings, the Sovtek was (in the context of my system) the clear winner. Space, air, harmonic balance, etc. were all superior.

Anyway, so I sent a bunch of tubes, wires (interconnects and power cords) and my power conditioner out to be Cryo'd.

Upon their return, resisting the temptation to "eat it all at once," I inserted and listened to one cryo'd component at a time.

My biggest surprise (although I expect that you will all think I'm crazy) was the extent of the change made by the Cryo'd power chords.

Initially, the interconnects sounded worse than the ones I had in the system, but I remembered reading that some stuff would need to be broken in again. As I write this they have passed the untreated cables.

Getting to the effect on the tubes, well you are just going to have to try it yourself. You would not believe me.

The changes to the sound are in some ways obvious, but in other ways more subtle. There is a relaxed "naturalness" to the music. Dynamics are better at both ends of the loudness scale. The sound seems much more like the master tape, even with my CD source. You have seen these words before, but here they are again: Great recordings disappear as recordings, that is, there is just the music. Good recordings (some of them, anyway) become very good. And even some studio cooked recordings can be startling, particularly the ones made in the early 60s.

Last night, my wife and I went to a performance by a local choral group and a youth symphony at the Gussman Hall on the campus of the University of Miami. At live performances, I make a point of closing my eyes at times and focusing on the sound (BTW, both the choral and orchestral performances were great. Sitting close to the orchestra, I was reminded how loud unamplified music can get during the performance of Copeland's "Rodeo."). Getting home, I put on the system, and besides once again being reminded how far we have yet to go in performance reproduction, I was very pleased with the recreation of some of the cuts of the Mormon Tabernacle Choir, and, of course Cantate Domino. Once I nailed the volume, I got it to sound very live.

Anyway, the TAD-1000 and my updated Von Schweikert speakers continue to satisfy me. Both are great values. I still don't think I've reached their limits.

I just tried some of Sandy's vibration isolators between the top and bottom speakers, the VRs are in two parts, and picked up a bit more clarity. The isolators really work. In my experience the better your system is, the easier the vibration reduction tweaks are to hear, and the effects are cumulative.

That's it for now. Thanks for reading.
ST0944,

Did you ever get around to rolling KT-77's in these amps? If so, what were your findings? Thanks.
While it is far too soon to do a full evaluation, having the amps just about two weeks, my experience mirrors that of Bamabubba. So far my preferences have been for triode mode, with the feedback control one click to the right of center.

At this time, however, I am not the best one to discuss break in.

I recently received my upgraded Von Schweikert speakers back from the factory (VR 4 to 5/7 "Pheonix" upgrade), and although I am past the intial phase, they are still breaking in themselves. BTW, Albert Von Schweikert and his staff also represent the best in customer service, like Paul with his products, they want to ensure that you get the most out of them. (Great sound, great service, reasonable price. That is real value). The speakers started to sound great with my older tube amps, but with the TAD-1000s they are crossing into "amazing" territory.

I am not an audio newbie, and have listened to and evaluated many products and systems over the years, and have learned to be cautious with praise. Over the years, I have experienced the feeling of being "blown away" a few times, by equipment that seems to do more than incrementally improve on the competition, and brings the sense of of a live event much closer. However, sometimes, after further listening, flaws are revealed and the equipment does not seem quite so great.

After living with both admittedly only a short time, collectively, the VR Pheonix mod speakers and the TAD-1000 monoblocks together represent the former experience (blown away), with no hint yet of the latter (disenchantment). In fact the sound may be getting better (or as my friend Harvey says, I am getting used to it).

A few weeks ago, while in Chicago, my wife and I caught a performance of the Chicago Symphony with Charles Dutoit. Seats were pretty good (lower balcony, near center). Whenever I attend a live performance, perhaps like many an audiophile I make mental note of the characteristics of the sound. I was surprised (pleasantly) by how remarkably well some of the classic Reiner-Layton-Mohr recordings in that venue sounded (Get the JVC XRCDs, if you can). These recordings are well know to most audiophiles (Scheherezade, Lt. Kije, etc.). My updated system was able to mimic most of the characteristics of that hall with startling veracity. Tonally, instruments sound like themselves. There is a mountain of "air." Background quiet (after around 9:00 PM, anyway) is eerie. You can hear all of the slight, normally obscured, rustling sounds made by the musicians.

Only in the dynamic domain does the system fall short. However, DO NOT take that as a critisism of the system. The system provides a "sense" of the dynamics far better than most I have heard. But, I have never heard any system capable of replicating the dynamic reality created by the CSO in Orchestra Hall, and I doubt one (for the home) exists. Or, perhaps the recordings do not capture the full dynamic range. I leave that discussion to experts.

This is not a review. Just early feedback. Perhaps I will say more when the system is fully broken in, whenever that is (how does one know?).

I am curious if other owners have compared the sound of the TAD-1000s with EL34s versus KT88s, 6550s or KT90s. I wonder if 6L6s work? Some folks love that tube.

A special "Thank you" goes to Sandy from Levyphoto.com, one of the top sellers of specialty tubes on Ebay, and another great guy, whose trained ears helped me get the amps set up, and whose GOLD PIN Ei ELITE GRAY PLATE 12AX7 tubes really, really sweetened the sound. Amazing! Sandy, I will be ordering more, and am looking forward to trying your KT77s.

And another thank you to friend and old tube equipment guru Harvey R. for keeping me grounded, and providing technical guidance.
While it is far too soon to do a full evaluation, having the amps just about two weeks, my experience mirrors that of Bamabubba. So far my preferences have been for triode mode, with the feedback control one click to the right of center.

At this time, however, I am not the best one to discuss break in.

I recently received my upgraded Von Schweikert speakers back from the factory (VR 4 to 5/7 "Pheonix" upgrade), and although I am past the intial phase, they are still breaking in themselves. BTW, Albert Von Schweikert and his staff also represent the best in customer service, like Paul with his products, they want to ensure that you get the most out of them. (Great sound, great service, reasonable price. That is real value). The speakers started to sound great with my older tube amps, but with the TAD-1000s they are crossing into "amazing" territory.

I am not an audio newbie, and have listened to and evaluated many products and systems over the years, and have learned to be cautious with praise. Over the years, I have experienced the feeling of being "blown away" a few times, by equipment that seems to do more than incrementally improve on the competition, and brings the sense of of a live event much closer. However, sometimes, after further listening, flaws are revealed and the equipment does not seem quite so great.

After living with both admittedly only a short time, collectively, the VR Pheonix mod speakers and the TAD-1000 monoblocks together represent the former experience (blown away), with no hint yet of the latter (disenchantment). In fact the sound may be getting better (or as my friend Harvey says, I am getting used to it).

A few weeks ago, while in Chicago, my wife and I caught a performance of the Chicago Symphony with Charles Dutoit. Seats were pretty good (lower balcony, near center). Whenever I attend a live performance, perhaps like many an audiophile I make mental note of the characteristics of the sound. I was surprised (pleasantly) by how remarkably well some of the classic Reiner-Layton-Mohr recordings in that venue sounded (Get the JVC XRCDs, if you can). These recordings are well know to most audiophiles (Scheherezade, Lt. Kije, etc.). My updated system was able to mimic most of the characteristics of that hall with startling veracity. Tonally, instruments sound like themselves. There is a mountain of "air." Background quiet (after around 9:00 PM, anyway) is eerie. You can hear all of the slight, normally obscured, rustling sounds made by the musicians.

Only in the dynamic domain does the system fall short. However, DO NOT take that as a critisism of the system. The system provides a "sense" of the dynamics far better than most I have heard. But, I have never heard any system capable of replicating the dynamic reality created by the CSO in Orchestra Hall, and I doubt one (for the home) exists. Or, perhaps the recordings do not capture the full dynamic range. I leave that discussion to experts.

This is not a review. Just early feedback. Perhaps I will say more when the system is fully broken in, whenever that is (how does one know?).

I am curious if other owners have compared the sound of the TAD-1000s with EL34s versus KT88s, 6550s or KT90s. I wonder if 6L6s work? Some folks love that tube.

A special "Thank you" goes to Sandy from Levyphoto.com, one of the top sellers of specialty tubes on Ebay, and another great guy, whose trained ears helped me get the amps set up, and whose GOLD PIN Ei ELITE GRAY PLATE 12AX7 tubes really, really sweetened the sound. Amazing! Sandy, I will be ordering more, and am looking forward to trying your KT77s.

And another thank you to friend and old tube equipment guru Harvey R. for keeping me grounded, and providing technical guidance.
Thanks for the review, I've had my mine for 1 1/2 weeks now and like what I'm hearing so far. I'm also using mine with the Tad-150 Signature preamp. I do think the break in for these may last a little longer then you stated. weather real or imagined mine continue to sound better each day I listen to them but then again I just purchased a used pair of Quad EL21's that are only four months old used exclusively in an apartment and don't think are fully broken in yet. You can only listen to music so loud in those confines without making enemies or being evicted. These speakers are just "stupid good" for the money and so far this has been a great combo. I currently prefer listening in the pentode mode but that may change but all the standard audiophile terms apply here: great soundstaging, depth, imaging and did I mention good tight bass that is more then adaquate for my 20x18 room. It's way too soon to give a formal review but I think Paul's got a winner here. BTW I was also wondering if anyone had tried using kt88 tubes and if so how they sound.

Ken
You mention at the bottom of your post the Antique sound labs 845s - is this a comparison? Did you have a pair of these or are you saying that they may be similar in type?